Alternative screening method for analyzing the water samples through an electrical microfluidics chip with classical microbiological assay comparison of P. aeruginosa

Talanta ◽  
2020 ◽  
Vol 219 ◽  
pp. 121293 ◽  
Author(s):  
Ismail Bilican ◽  
Tolga Bahadir ◽  
Kemal Bilgin ◽  
Mustafa Tahsin Guler
Keyword(s):  
Water Samples ◽  
Screening Method ◽  
Microbiological Assay

Wide-Scope Determination of Pharmaceuticals and Pesticides in Water Samples: Qualitative and Confirmatory Screening Method Using LC-qTOF-MS

2018 ◽  
Vol 229 (12) ◽  
Author(s):  
Juliana Bazzan Arsand ◽  
Rodrigo Barcellos Hoff ◽  
Louíse Jank ◽  
Alexsandro Dallegrave ◽  
Carolina Galeazzi ◽  
...  
Keyword(s):  
Water Samples ◽  
Screening Method ◽  
Wide Scope ◽  
Pesticides In Water

Liquid Chromatographic Screening Method for Fluorescent Derivatives of Chlorophenoxy Acid Herbicides in Water

1992 ◽  
Vol 75 (4) ◽  
pp. 720-724 ◽  
Author(s):  
Toshinari Suzuki ◽  
Satoru Watanabe
Keyword(s):  
Solid Phase Extraction ◽  
Water Samples ◽  
Solid Phase ◽  
Screening Method ◽  
Ethyl Esters ◽  
Separate Determination ◽  
Phase Extraction ◽  
Liquid Chromatographic ◽  
Acid Herbicides

Abstract A liquid chromatographic method for screening 9 chlorophenoxy acids (2,4-D; 2,4-DP; 2,4-DB; MCPA; MCPP; MCPB; 2,4,5-T; 2,4,5-TP; and 2,4,5-TB) and their ethyl esters in ground- and tap water is presented. The water samples are acidified and subjected to either liquid-liquid or solid-phase extraction. The extracts obtained are saponified in 0.03N NaOH-50% methanol (1+1) and the acidic compounds are re-extracted with ethyl acetate-n-hexane (8 + 2) after acidification and derivatized with 9- anthryldiazomethane. Derivatized compounds are analyzed using reversed-phase column chromatography with fluorescence detection (excitation, 365 nm; emission, 412 nm). Recoveries of analytes from 20 mL water samples were greater than 90%, and the average coefficient of variation was within 5.0% at 0.5 ppb for both extraction methods. These methods are simple and useful for the determination of small amounts of chlorophenoxy herbicides. Solid-phase extraction is suitable for screening a large number of samples simultaneously, and liquid extraction for separate determination of the acids and ethyl esters of the herbicides was improved by introducing a saponification step.

scholarly journals Screening method for the determination of selected tetracyclines in water by liquid chromatography with diode array detector

2014 ◽  
Vol 58 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Ewelina Patyra ◽  
Ewelina Kowalczyk ◽  
Krzysztof Kwiatek
Keyword(s):  
Oxalic Acid ◽  
Water Samples ◽  
Solid Phase ◽  
Screening Method ◽  
Gradient Elution ◽  
Environmental Water ◽  
Array Detector ◽  
Chromatographic Procedure ◽  
Oasis Hlb

Abstract A chromatographic procedure for determination of oxytetracycline (OXT), tetracycline (TC), chlorotetracycline (CTC), and doxycycline (DC) in water samples was developed and was applied for the analysis of water samples collected from poultry and pig farms and environmental water samples. Samples were acidified with trifluoroacetetic acid to pH 3 and further purified by solid phase extraction using Oasis HLB cartridges. The samples were dried up and redissolved in the mixture of oxalic acid and methanol. Separation was performed on reserved phase column (Phenomenex column C18 , 250 mm × 4.6 mm, 5 μm) by multistep gradient elution, and detection was carried out at 360 nm for OTC and TC, 370 nm for CTC, and 350 nm for DC. The tetracyclines were eluted with the mobile phase of 0.05 M oxalic acid (pH 2.5), acetonitrile, and methanol. This method provided average recoveries of 83.53% to 108.59%, with coefficient of variations (CVs) of 2.41% to 8.64% in the range of 10 to 1000 μg/L OTC, TC, CTC, and DC in water. The linearity for the tetracyclines was determined by HPLC-DAD in the range 10 to 1000 μg/L, with the correlation coefficient (R) > 0.99. The LOD and LOQ for the tetracyclines in water samples ranged from 1.51 to 4.00 and 2.51 to 5.93 μg/L, respectively.

Direct determination of halogenated POPs in aqueous samples by in-tube SPME, focalization and GC-ECD analysis

RSC Advances ◽  
2015 ◽  
Vol 5 (14) ◽  
pp. 10418-10423 ◽  
Author(s):  
M. V. Russo ◽  
P. Avino ◽  
E. Veschetti
Keyword(s):  
Organic Pollutants ◽  
Persistent Organic Pollutants ◽  
Water Samples ◽  
Screening Method ◽  
Direct Determination ◽  
Simultaneous Analysis ◽  
Aqueous Samples ◽  
Ultra Trace

A rapid analytical screening method allowing simultaneous analysis of few halogenated persistent organic pollutants (POPs) in water samples at ultra-trace levels was developed.

scholarly journals Rapid Screening Method for the Total Petroleum Hydrocarbons in Water Samples by Solid-Phase Microextraction and GC-MS

2012 ◽  
Vol 14 (2) ◽  
pp. 177 ◽  
Author(s):  
M.B. Alimzhanova ◽  
M.B. Abilev ◽  
M.M. Kuandykova ◽  
B.N. Kenessov ◽  
D.K. Kamysbayev
Keyword(s):  
Water Samples ◽  
Petroleum Hydrocarbons ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Screening Method ◽  
Extraction Time ◽  
Total Petroleum Hydrocarbons ◽  
Extraction Temperature ◽  
Fiber Coating ◽  
Spme Fiber

Determination of total petroleum hydrocarbons (TPH) in water is an important tool for monitoring of contamination due to oil spills or leaking storage tanks. In this study, a screening method for the quantification of total petroleum hydrocarbons in water based on solid phase microextraction (SPME) in combination with gas chromatography – mass spectrometry (GC-MS) is presented. Extraction of hydrocarbons from water samples were conducted by SPME fiber coating placed into the headspace above water. Petroleum hydrocarbons were desorbed from the fiber coating in the injection port of gas chromatograph. The effect of the following parameters affecting the distribution of the analytes between three phases on the response of TPH were studied: SPME fiber coating type and dimensions, extraction temperature, extraction time and pH. The optimized method uses 100 μm polydimethylsiloxane fiber coating, extraction time 600 s, extraction temperature 80 °C, without addition of salt at basic pH. The developed method was successfully applied for detection of total petroleum hydrocarbons in water taken from Koschagyl oil fields and Koschagyl village.

Automated Analytical System for Phenols Incorporated into Screening Method Suitable for Determination of 2-Methyl-4-chlorophenoxyacetic Acid and/or 2,4-Dichlorophenoxyacetic Acid Herbicide Residues in Water

1977 ◽  
Vol 60 (1) ◽  
pp. 218-223
Author(s):  
Daniel E Ott ◽  
Hakon O Friestad
Keyword(s):  
Water Samples ◽  
Methylene Chloride ◽  
Limit Of Detection ◽  
Screening Method ◽  
Colorimetric Method ◽  
Free Phenol ◽  
Chlorophenoxyacetic Acid ◽  
Water Response ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Acid Herbicides

Abstract 2-Methyl-4-chlorophenoxyacetic acid (MCPA) and 2,4-dichlorophenoxyacetie acid (2,4-D) are extracted from water with methylene chloride and are degraded when heated in the presence of pyridine hydrochloride to their corresponding phenols which are determined automatically with a modified distillation-colorimetric analyzer system. The method has been evaluated primarily with surface water samples collected from areas of known MCPA applications. The lower limit of detection of MCPA is about 50 µg/L water. Response for 2,4-D is almost identical to that for MCPA at equal concentrations. Comparative responses to other potential responding phenoxy acid herbicides have not been determined. MCPA results from this method for several water samples compared favorably with results from a gas chromatographic method. The scntiautontated colorimetric method can be applied to water samples of unknown history as a screening method in which case a significant, positive recorder response, suitably corrected for free phenol response as suggested herein, indicates probability of presence of one or more of the responding herbicides. The sample would then need to be examined by other, more definitive means.

Microbiological Assay for Antibiotics in Surface Waters

1983 ◽  
Vol 66 (3) ◽  
pp. 635-639
Author(s):  
Jack M Katz ◽  
Stanley E Katz
Keyword(s):  
Surface Waters ◽  
Water Samples ◽  
Potassium Phosphate ◽  
Microbiological Assay ◽  
Direct Addition ◽  
Assay Conditions

Abstract Assay procedures were developed for determining bacitracin, chlortetracycline, erythromycin, oxytetracycline, penicillin, streptomycin, and tylosin residues in surface waters. Direct addition of solid potassium phosphate buffering salts to water samples enabled suitable pH adjustments for optimum assay conditions. Recoveries from 2 surface waters averaged 97.9 and 102.7% for chlortetracycline, 101.0 and 101.5% for bacitracin, 94.5 and 95.3% for erythromycin, 84.2 and 89.8% for oxy tetracycline, 82.3 and 97.5% for penicillin, 97.4 and 99.2% for streptomycin, 87.4 and 94.2% for tylosin.

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